Stephen Báthory (aka István Báthory; Polish: Stefan Batory), b 27 September 1533 in Transylvania, d 12 December 1586 near Hrodna, Belarus. Transylvanian prince (1571–6) and Hungarian king (1576–86) of Poland. One of the most forceful and ambitious monarchs in the history of Poland, he attempted to form a great state from Poland, Muscovy, and Transylvania. To defend Poland's eastern Baltic provinces against Russian incursion (eg, in the war with Ivan IV, 1579–82), he strengthened the Polish army by increasing the numbers of registered Cossacks and granting them privileges. In 1578 he allowed them to use the Trakhtemyriv Monastery as a hospital and refuge.